Alastair Reynolds was asked about these pronouns in his blog comments (many people have simply assumed it was a typo or a mistake in the printing process). He replied in another comment:
They’re not errors – those are gender-neutral pronouns for the character Travertine.
This means the pronouns are a deliberate attempt not to imply a male or female gender for the character. Gender-neutral pronouns aren’t in particularly common use, but they do exist, and this is just one such example.
There’s a good explanation of gender-neutral pronouns, and a list of others that you might encounter, on Wikipedia. Of this particular pronoun, Ve, it says this:
Proposed by New Zealand writer Keri Hulme some time in the 1980s. Also used by writer Greg Egan for non-gendered artificial intelligences and “asex” humans.
Note that the Wikipedia entry also has a list of the different forms of the pronoun, which seems to line up with the list in your question.